Artificial denture



Oct. 9, 1951 J. D. KINSLEY 7 2,570,562

ARTIFICIAL DENTURE Filed Feb. 24, 1948 FIG. 9

IN V EN TOR. J. D. K lNSLE Y ATTORNEY Patented Oct. 9, 19 51 2,570,562 iR IFI'cI L man-Tm... Jason D. Kinsley, Cedar RapidaIoWa" 1 ApplicationFebruary 24, 1948. serial No. r0394 present invention relates toartificial human teeth and more particularly to the occjlusa'l surfacethereof and the method by which such surface is produced. The principalobjective of my invention is to produce a set of bicuspid and molarteeth which are adapted to form a balanced occlusion. This isestablished by intraorally milling a set of abrasive bite rims to, aperfectly balanced occlusion to serve as a pattern fo'rjJthe occlusalcontour of the teeth, whereby to .producea proper relation betweenthe'mandibular and maxillary teeth.

In order to produce a perfectly balanced clusion throughout the entirerange of the mandibular function, it is necessary that certainrequirements be met. I have found that, by the porting gum ridges duringintraoral milling procedure. This is produced by a rotation. of theright condyle within the glennoid fossa and asimultaneous downward andforward move-, ment of the left condyle in its. path but, when themandible moves leftward from the centric position, the action isreversed and thereis rotation of the left condyle in-the glennoidflfossaand a simultaneous downward and forward movement of the right condyle inits path, thus shifting the direction of movement. As this shiftingtakes place, a rocking or tiltingof the base platesupon the supportinggum ridges. is caused. To overcome this difficulty, I first mill theprotrusive curvature and then cut anarrow groove in the upper rim onboth the right and left sides along the lines of the lingual bicuspidand molar cusp area. I then fill these grooves with a hard abrasivecement which will not become distorted upon lateral milling. I thencarve away'the lateral borders from thecement, leaving it in the form ofa prominent crest. The case is then placed in the patients mouth and heis asked to move his jaw laterally toward the right and left. Thiscauses milling in of the lateral concavity and inclination 'on the lowerbite rim. The right and left movements 'from centric position areseparate and independent. By these actions, the left lingual and rightbuccal slopes are simultaneously milled upon the leftward movement ofthe mandible, while, upon rightward movement, the right lingual and leftbuccal are milled. By the (opera;

1 Claim. (-01. 32-3) movements of the mandible. The case is then keyedinrcentric and mountedupon an articue lator, the cement crest removedfrom the upper rim and replaced .with alayer of heatsoftened tionsdescribed, a perfectly-balanced occlusion is a established, both as toprotrusion and lateral modeling compound and, with the lower rim coldand wet, the articulator is then closed, thus forming a counterpart ofthe'lower milled occlusal surface in the compound on the upper rim. Thelower. teeth are then set to correlate with the described counterpartand then the upper teeth are set to articulate with the lower teeth, theteeth being made to simulate the occlusal surfaces ofthe milled biterims. i

In the drawings annexed hereto and forming a part hereof, j r

Fig. 1 shows a cross-section of both upper and lowerdentures in centricrelation;

' Fig. Zshows a mandible moved to one side and insuch contact with theupper teeth that thereis no rocking of the denture on a gumridge; Fig. 3showsfthe formation of a concavity in the occlusal surface of the lowerbite rim during the milling in process; v v v I Fig. 4 shows avariationin inclination of the surfaces of occlusion, which variationoccurs in some mouths, and in'varying degrees, and shows,

also, on "the right side, the'fis sures in thelower occlusal surface asbeing arranged transversely to'the'movement of the mandible;

Fig. 5 shows the form ofjan occlusal surface of a set of bicuspid andmolar upperteeth;

Fig. 6 shows the occlusal surface of a set of lower molar and bicuspidteeth with a pair of lines thereon indicating the relative direction ofmotion of the correlated teeth during mastication;

Fig. 7 shows upper and lower correlated teeth with the concavity in theocclusal surface of the lower teeth indicated by dotted lines; v

Fig. 8 .shows a curvature in the occlusal surface of the lower firstbicuspid tooth; and p Fig. 9 shows a greater curvature surface ofocclusion in the third molar area. I 7 Reference will now be made ingreater detail to the annexedzdrawings for a morecomplete description ofthis invention. Figs. 1 and 2 show how the dentures are balanced, whenproperly constructed, to 1 prevent tilting of one by the other, duringmastication. When the upper and lower dentures I and 2 are constructed,the occlusal surface of the lower teeth'3has a concave curvaturelaterally, as well as longitudinally, and the upper contacting area isin the form of anridgeorbrest A, the occlusal surface of the 'lowerteeth3 being formed infacs'imile to the milled occlusal surface of the lowerbite rim and the upper teeth 6 in accordance with the cement crest la,as shown in Fig. 3, the upper teeth 6 having a crest or ridge 4constructed along the line of the lingual cusps which project downwardlyinto engagement withthe lower teeth 3. By a comparison of Figs. 1 and 2,it will be seen that the pressure-bearing surface of the upper teeth ismaintained substantially directly in line. with the crest of; theuppergum ridge so-that" there is-no tendency to causerock ing of the upperdenture l, as would be the case if the area of pressure were outside ofthe linesa:

and b, as in the case of an upper buccal, cusp,

contact. The position of the lower gum ridge is indicated by the lines 0and d, therebeing-ta; greater span between 0 and 11 than between a andFrom Fig; 1 it is noted" that the downward pressure of the upperteethwb, in the average case.

on the lower is located inside of the lines 0 and d. Thistends,.to..prevent any rocking of the lower denture 2.

From Fig. 2 it willbe. noted that. the pressure on the lower teeth atone side of. the. mouth is. buc.-, eallyfrom thegumcrest while, upon theother sideof the mouth, the. pressure is linguallyfrom the gum crest.Therefore, if there is any tendency by reason of the pressure on thebuccal side of the teeth to. cause tilting of that denture upon the..gum.ridge, the pressure on the lingual cusp at the opposite. sideof the.mouth holds. the den.- tu te down on the gum. ridge so that there is notilting thereof, this,b.ei ng upon the working side whichdefinitely.precludes. a tilting action, It will also be seen, from, particularly,Figs. land Zpthat vvhethen the. teeth .are closed in centric position,as inFig. 1., orare laterally. displaced, as.:i.n Fig. 2., portionsoftheupper teethlie. sufflcientlyoutwardly of the. contacting ridge.-nQrtiorns l to.- prevent h cheek from bein drawn in between the upper:and. lower teeth and bitten thereby, much. tothe di comfort, and injuryof the patient. I The. biterimsare formed with a slightlygreaterbiteopening-thannormal. Then, by aprotrusire movement of the. mandible,a? protrusive curvature is milledon the occlusalsurfaces oftherbiterimsfiaand 8, as. shown in Fig. 7. Then a narrowgrooveliscutinthe'upper rim along the line ofthe lingual cusps. Thisgroove is then filled with an abrasive cement la which is sufl l cientlyrigid. to maintain its: form throughout thelateral millin procedure.This cement is shown in;F!ig. 3 at la. Next, the. bite: rim is-cut away,laterally from the. cement, leaving it in the form of a prominent crest.Next, the. case. is placed in the patients, mouth. and, by. lateralmovement o-fthe mandible, the curvature and in; clination are formed, asdescribed above.

The variationv in inclination of the occlusal surface. of the lowerteeth is shown by the linese and. I; Eise. t a h d draw n s, are m relyi Laud show ome oi he a ions which may occur as, a result of milledregistra- .tion.

Fig; 5 shows the locationof the crest 4.011. the

es-zslusal ur e in. aa tf pp r mo a nd .bicuspidteeth. asbeing placedlingually from the cen ral line. t e e Fig. 6 shows the. occlusal,surface of a set of lower molar and bicuspid teethhavinga 0,011.- cavity 3a produced by the, described, intraoral milling procedure.Thissurface, is provided with engraved fissures, on lines transverse tothe. movemerit. oi; the. mandible. on the, lingual, ide, the

4 direction of which is indicated by the line g and h. The food ispressed into these fissures during mastication and, by the action of theupper crest in moving laterally during the act of chewing, the food iscrushed and sheared.

Fig. 7 shows the buccal aspect of molar and bicuspid teeth when set incentric relation showing the spacing between the buccal cusps thereof,the dotted line showing the contact of the upper li ual; crest area withthe occlusal surface of the lower-teeth midway-between the lateralborders thereof.

Fig. 8 shows the laterally milled occlusal curvatllleof a .lower firstbicuspid tooth as being less than that of a lower third molarillustrated in Figit, the line... 9 indicating the former and the linevIjl indicating the latter, these being illustrative of typicalcases.The change in curvatureis, progressive between these teeth.

In order to make the; method clear, the same willnow be setout. i der-vr t. ca s. ar ade. of the Jaws. to. efit e nd nrl tos molded e hese. c tN xt. e. ms. are mo d d. h. hepla a e t e ite ms. are trinnned toapproximate the bite opening although they are left a little oversize inorder to have. enough. material for the milling in which follows next.Th s on st a h s me. of n: traorally milling the, protrusive curvature.When this. s.v completed. a r ov is. t ne. h ine. or. the upper lin u lo ar and. b uspid usps; When this is completed, the grooveisfilled flushwithabra iye cement. whi h wills t hard. n ugh to withstand intraoralmilling. The case. is then inserted nto the. pat en s mo h nd s n:structe to move th ma di le t allyr ight. and left. nt lthe cc usi n cnca i y ave been iormedinthe low r. m. and. a a ance occlus on is.,stabl shed.-.

caseisthen ounted ar q ator n... attic elatio The. ment c st, is then. r

m ed. rom hempper pl t nd aced th. a h -so ened... m del omp un heo errimbeing wet and cold; Now, withthemgdel' ine omp ndso t he r icula or ilqs li orm.- me. a oun rpar f. th o rrim. pon. the pri rbese p te. Myower t a madam confo m t he pp r ount r a thus pro: uc ne r r aof e r. ml edoc l al sura-ca Nex y p r et e' o med ith a i ext ndin l n e, areahengual cusps. Now, the teeth are set up with theridge so placedthat it,only, can contact the lower e ih.. d: h a p s on. subst t y midi waybetween the lingual and buccal borders thereof, when in centricrelation. The set up teethpow. forma replica ofthe intraorally. milledbite-rims. Starting from centric position, it will be observed, fromFig. 2, that upon lateral movement; as the mandible moved rightward, theright up er. ridge ides p n' t e. ri in a lopes and, simultaneouslytherewith, the left upper ridge slides upon the left buccal; slopes ofthe ole his l; urfaces. f: e, 10Wer h.-v i a ly a themandibl'emovesleftward, the left upper ridge slides upon the left lingual slopes, ofthe sclusalfiu fa s he er hahd. 111.1 aneo sly e w h he i h p r. id idesuponthe right buccal slopes of the lowerocclus al ur ac s.

It s .of. ou se. nder ood, a he p ci c escr r on t ctu e et o th ov a hed'eparted'from Without departing fromthe spirit o y his nv htion asseorth h einahd as' er fiued th ppended c aim.

- 5 Having now described my invention, I claim: REFERENCES CITED denturem whlch the lower molar and 1010115 The following references are ofrecord in the pid teeth have their occlusal surfaces formed as file ofthis patent; a concavity extending laterally of the mandible. the upperteeth having a longitudinally extend- 5 UNITED STATES PATENTS ing ridgeon their grinding surfaces, the lateral Number Name Date curvatures ofthe concavity being less in the 1,681,436 Sears 1 1s e Aug. 21, 1928first .bicuspid than in the second molar, and the 1,878,517 HiltebrandtSept. 20, 1932 change in curvature being progressive. 2,095,432 Brenners Oct. 12', 1937 JASON D. KINSLEY. 10 2,168,530 Kyprie r l e Aug. 8,1939 2,171,759 Meyer 11... Sept. 5, 1939

